Cardiovascular Complications of Radiotherapy

Chest radiotherapy is routinely used to treat malignancies such as Hodgkin disease and breast cancer but is commonly associated with a variety of cardiovascular complications involving the pericardium, myocardium, valves, coronary arteries, and conduction system. Cardiovascular complications are related to the total dose of radiation and the fractionation of the dose. They are usually progressive, portend poor prognosis, and are often refractory to treatment after significant radiation exposure. The mechanism of injury is multifactorial and likely involves endothelial damage of the microvasculature and coronary arteries and liberation of multiple inflammatory and profibrotic cytokines. In conclusion, routine follow-up with a cardiologist, which might include screening for valvular disease with echocardiography and coronary artery disease with computed tomography angiography or coronary artery calcium scoring, should be considered in patients with a history of chest radiotherapy. 2013 Elsevier Inc. All rights reserved. (Am J Cardiol 2013;112:1688e1696) Chest radiotherapy is commonly used to treat malignancies such as breast cancer and Hodgkin disease but is associated with a variety of cardiovascular complications including involvement of the pericardium, myocardium, valves, coronary arteries, and conduction system, depending on the type and amount of radiation. Autopsy of young patients reveals that cardiovascular injury after radiation is unlikely because of age-related degenerative changes. 1,2 Chest radiotherapy is used in 37% of patients with early breast cancer, 3 and randomized trials of radiotherapy for breast cancer have reported increased risk of cardiovascular mortality. 4 Cardiovascular disease was the third most common cause of death in patients with Hodgkin disease followed long term after radiotherapy, accounting for 12% to 16% of mortality. 5,6 Cardiac involvement was observed in 96% of patients who were evaluated by echocardiography, radionuclide angiocardiography, and cardiac catheterization, including constrictive pericarditis (although the more accurate term is “pericardial constriction” given that there is very little inflammation in the fibrous tissue causing the constriction) in 50% of patients, coronary artery disease in 12%, and left ventricular dysfunction in 4%. 7 Patients who received radiotherapy to a portion of the heart had increased risk of valve replacement or surgical or percutaneous revascularization compared with the general pop